Motor vehicles contain numerous lighting devices for both interior and exterior illumination. For example, exterior vehicle lighting devices may perform stop light functions, taillight functions, headlight functions, daytime running light functions, dynamic bending light functions, and fog light functions. Numerous studies have found that nighttime visibility is a key to highway safety. It's been reported that more than half of all traffic deaths occur after dark.
In an effort to improve vehicle and pedestrian safety, most governments promulgate some form of safety regulations that specify motor vehicle lighting performance requirements that ensure adequate illumination of the roadway and enhance the visibility of motor vehicles on the roads so that their presence is perceived and their signals understood in daylight, in darkness, and in conditions of reduced visibility. For example, as of the date of this filing, Federal Motor Vehicle Safety Standard (FMVSS) No. 108 specifies various maximum and minimum photometric intensity values (based on angle) for headlights on vehicles operated within the Unites States. In addition to these requirements, the Insurance Institute for Highway Safety (IIHS) has its own set of tests and ratings (Headlight Test and Rating Protocol) for headlight performance. The IIHS tests and ratings seek to encourage manufacturers to improve the illumination performance in actual on-road use. IIHS evaluations have shown that the on-road illumination provided by vehicle headlights varies widely. And the majority of headlights that IIHS has rated are poor (insufficient illumination, cause excessive glare, etc.).
Vehicle manufacturers must design vehicle lighting devices to meet the technical requirements of these or similar standards around the world. In recent years, vehicle lighting has also become important for its aesthetic appeal to consumers. Thus, vehicle manufacturers have made an effort to design vehicle lighting devices in consideration of the styling of the vehicle on which the lighting devices are mounted. Further, vehicle manufacturers may provide optional lighting effects (in addition to the required lighting functionality) to enhance a vehicle's illumination performance and styling.
It may be technically challenging to provide aesthetically appealing vehicle lighting devices while also meeting the necessary cost, technical, and regulatory requirements. For example, headlights on currently manufactured cars and trucks typically use significant power and require various additional components such as reflectors, lenses, cut off devices, and the like. Aesthetic lighting effects lead to an even greater number of components and complexity. Such vehicle lighting devices often are not easily adapted to the styling of the vehicle.
In recent years, a number of vehicle manufacturers have begun using light-emitting diodes (LEDs) in an effort to meet desired lighting performance, reduce power and provide improved aesthetic characteristics.
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as conventional art at the time of filing, are neither expressly nor impliedly admitted as conventional art against the present disclosure.